Zero headspace extractors are used to perform the EPA toxicity characteristic leaching procedure to analyze volatile organic compounds. Commercially available zero headspace extractors all use stainless steel cylinders which must be cleaned and o-rings that are susceptible to decomposition. The sample is in contact with the vessel, therefore the extractor must be disassembled, cleaned and reassembled after each extraction. This increases the amount of labor required for each extraction and makes the zero head space extractor impractical for use with highly radioactive samples. These must be handled with manipulators, which are difficult to use and provides a greater opportunity for error.
U.S. Pat. Nos. 4,864,877 and 4,974,456 (both to Ortiz et al.) disclose zero headspace devices. These patents, which have related disclosures, the latter being a divisional of the former, disclose zero-headspace sampling containers intended to meet EPA sampling requirements for liquids, and not for multi phase samples, such as solvent-treated soil samples. Ortiz et al. do not disclose filtration means to retain sediment and do not disclose pressurized containers.
U.S. Pat. Nos. 5,470,535 and 5,607,234 relate to extractor vessels designed for agitating a sample mixture comprising a solids-containing sample and an extraction liquid, which include a separator or filtration means through which the sample mixture can be discharged under pressure. None of the constructions of these prior patents is suitable for meeting the objects of the present invention.